Nowadays the trend of environmental protection and energy conservation makes the green energy industry, especially the electric vehicle industry continues to flourish. The demand of the power module(s) in the electric vehicle is enormous, of course, in use of the operation of power system must be safe. The reconfiguration of the power supply array, according to the condition of the application and the control of the system, is achieved by the physical switch to connect the power devices in series and parallel, to fulfill the needs for the actual system environment.
In general when reconfiguring the power supply modules, which has to be operated under the condition that the system load doesn't directly charge or discharge the power supply modules (that is, in the situation of “zero current” operation). Obviously it's very inconvenient that the reconfigurable power system is under the condition of dynamics loading, for example, driving electric vehicle on the roads. As mentioned above, for the safety reason, when switching the power switch to reconfigure the power system, it usually needs to break the connection between the system load and the power device first. A ┌dead-time┘ control strategy is necessary. Firstly turn the enable (or bypass) switch that previously on from on status to off, and then turn the bypass (or enable) switch that previously off from off status to on. This may prevent the shoot-through current being generated, and the power supply array can thus be switched or reconfigured. To be safe and sound, the power system needs an additional energy storage unit to help fulfill energy demand of the system load when reconfiguring the power device or power modules. This may lower the power transfer efficiency. In reality, it's not easy to reconfigure the power or battery modules during the long-term uninterrupted dynamic load requirements for driving the electric vehicle on the road.
Therefore, it is one of the recent rise research topic on how to solve the practical issues when using the power device or not (that is, turn on/off the enable/bypass switch), and reconfiguring the serial-parallel reassembly of the power device can be carried out easily under various dynamic loads as time goes by.